Vehicles for the elderly and the disabled such as electric wheelchairs and mobility scooters are not suitable for uneven terrains, slopes, and large steps. Wheelchairs are difficult to get on escalators. Further, mobility scooters cannot be brought on trains and buses. As there are concerns about accidents where mobility scooters fall sideways, the mobility scooters are not suitable for usage environments where steps and slopes are present on the sides of the mobility scooters, and thus the mobility scooters need to travel at a low speed in order to travel safely.
Patent Literature 1 discloses a wheelchair that can ascend and descend stairs. The wheelchair disclosed in Patent Literature 1 includes six wheels. Right and left front wheels are driving wheels. Two other wheels are arranged on one side of the wheelchair behind the right and left front wheels. The six-wheel grounded state enables the wheelchair to ascend and descend stairs. When the wheelchair travels on a flat surface, four wheels of the wheelchair are grounded. The wheels are coupled to a chair part with serial link arm mechanisms interposed therebetween. The wheelchair can ascend and descend stairs with different right and left heights by controlling the right and left serial link arm mechanisms.